Back to EveryPatent.com
| United States Patent |
6,131,047
|
|
Hayes, Jr.
, et al.
|
October 10, 2000
|
Radiotelephones having contact-sensitive user interfaces and methods of
operating same
Abstract
A radiotelephone includes a housing, and a radiotelephone communications
transceiver and display are attached to the housing. A contact-sensitive
transducer such as a resistive transducer, a capacitive transducer or a
semiconductive transducer, is attached to the housing and produces an
output signal that characterizes contact with a contact-sensitive surface
of the contact-sensitive transducer. A controller is responsive to the
output signal and operatively associated with the display and the
radiotelephone communications transceiver, and controls at least one of
the display and the radiotelephone communications transceiver according to
the output signal of the contact-sensitive transducer. The controller,
responsive to the contact-sensitive transducer, may determine a position
of contact along an axis of the contact-sensitive transducer. A graphical
object is selectively displayed based on the determined position of
contact to thereby identify the graphical object, e.g., by highlighting
one of a plurality of displayed graphical objects or by displaying a
cursor that indicates one of a plurality of displayed graphical objects.
In yet another embodiment, the controller is configured to cause the
display or the radiotelephone communications transceiver to perform a
plurality of actions. An action of the plurality of actions may be
associated with an identified graphical object, and the controller may
initiate the action associated with the identified graphical object in
response to, for example, detection of a momentary contact of an object
with the contact-sensitive transducer.
| Inventors:
|
Hayes, Jr.; John Joseph (Wake Forest, NC);
Thornton; Curtis Wayne (Cary, NC)
|
| Assignee:
|
Ericsson Inc. (Research Triangle Park, NC)
|
| Appl. No.:
|
001173 |
| Filed:
|
December 30, 1997 |
| Current U.S. Class: |
455/566; 345/173 |
| Intern'l Class: |
H04B 001/38; G09G 005/00 |
| Field of Search: |
379/433,428
455/556,575,95,550,90,566
345/173,168,156
|
References Cited
U.S. Patent Documents
| 3777222 | Dec., 1973 | Harris | 341/26.
|
| 4177421 | Dec., 1979 | Thornburg | 324/725.
|
| 4566001 | Jan., 1986 | Moore et al. | 345/173.
|
| 4647916 | Mar., 1987 | Boughton | 345/156.
|
| 4739299 | Apr., 1988 | Eventoff et al. | 338/99.
|
| 4810992 | Mar., 1989 | Eventoff | 338/99.
|
| 4870677 | Sep., 1989 | Di Santo et al. | 379/93.
|
| 5184120 | Feb., 1993 | Schultz | 340/870.
|
| 5422656 | Jun., 1995 | Allard et al. | 345/173.
|
| 5452240 | Sep., 1995 | Roca et al. | 364/705.
|
| 5459776 | Oct., 1995 | Di Santo et al. | 379/93.
|
| 5572573 | Nov., 1996 | Sylvan et al. | 455/556.
|
| 5584054 | Dec., 1996 | Tyneski et al. | 455/566.
|
| 5598527 | Jan., 1997 | Debrus et al. | 345/173.
|
| 5710810 | Jan., 1998 | Tiilikainen | 379/355.
|
| 5715524 | Feb., 1998 | Jambhekar et al. | 455/90.
|
| 5719936 | Feb., 1998 | Hillenmayer | 379/447.
|
| 5815142 | Sep., 1998 | Allard et al. | 345/173.
|
| 5859629 | Jan., 1999 | Tognazzini | 345/173.
|
| 5915228 | Jun., 1999 | Kunihiro et al. | 455/575.
|
| 5920310 | Jul., 1999 | Faggin et al. | 345/173.
|
| Foreign Patent Documents |
| 0 698 845 A1 | Feb., 1996 | EP.
| |
| 0 707 257 A1 | Apr., 1996 | EP.
| |
| 59-153342 | Jan., 1985 | JP.
| |
| 8-030378 | Mar., 1998 | JP.
| |
Other References
International Search Report, PCT/US98/27042, May 11, 1999.
VersaPad.TM., VersaPad Finished DataSheet,
http://www.interlinkelec.com/magic/page02g.htm, Oct. 9, 1997, pp. 1-3.
|
Primary Examiner: Eisenzopf; Reinhard J.
Assistant Examiner: Appiah; Charles N.
Attorney, Agent or Firm: Myers Bigel Sibley & Sajovec
Claims
That which is claimed is:
1. A radiotelephone, comprising:
a housing comprising a front surface and respective first and second edge
surfaces disposed on respective opposite sides of said front surface;
a radiotelephone communications transceiver, supported by said housing;
a display, supported by said housing, that displays an image at said front
surface of said housing;
a contact-sensitive transducer, supported by said housing and having a
contact-sensitive surface disposed at at least one of said first and
second edge surfaces, which produces an output signal that characterizes
contact of an object along said contact-sensitive surface of said
contact-sensitive transducer; and
a controller, responsive to said output signal and operatively associated
with said display and said radiotelephone communications transceiver,
which controls at least one of said display and said radiotelephone
communications transceiver according to said output signal of said
contact-sensitive transducer, wherein said controller is configured to
selectively display a graphical object on said display according to said
output signal of said contact-sensitive transducer, and wherein said
controller comprises means, responsive to said contact-sensitive
transducer, for scrolling displayed rows along an axis of said display
based on the output signal of said contact-sensitive transducer.
2. A radiotelephone according to claim 1, wherein said means for scrolling
comprises:
means, responsive to said output signal of contact-sensitive transducer,
for detecting moving contact with said contact-sensitive transducer along
said axis of said contact-sensitive transducer; and
means, responsive to said means for detecting moving contact, for scrolling
displayed rows along said axis of said display based on the detected
moving contact.
3. A radiotelephone, comprising:
a frame;
a radiotelephone communications transceiver, supported by said frame;
a display, supported by said frame;
a contact-sensitive transducer, supported by said frame, which produces an
output signal that characterizes contact of an object along a
contact-sensitive surface of said contact-sensitive transducer; and
a controller, responsive to said output signal and operatively associated
with said display and said radiotelephone communications transceiver,
which controls at least one of said display and said radiotelephone
communications transceiver according to said output signal of said
contact-sensitive transducer, wherein said controller has a first mode
wherein said controller is responsive to contact with said
contact-sensitive transducer and a second mode wherein said controller is
unresponsive to contact with said contact-sensitive transducer, and
wherein the radiotelephone further comprises means for placing said
controller in one of said first mode or said second mode in response to an
input from a user.
4. A radiotelephone, comprising:
a frame;
a radiotelephone communications transceiver, supported by said frame;
a display, supported by said frame;
a contact-sensitive transducer, supported by said frame, which produces an
output signal that characterizes contact of an object along a
contact-sensitive surface of said contact-sensitive transducer; and
a controller, responsive to said output signal and operatively associated
with said display and said radiotelephone communications transceiver,
which controls at least one of said display and said radiotelephone
communications transceiver according to said output signal of said
contact-sensitive transducer, wherein said controller comprises:
a first control circuit, responsive to said contact-sensitive transducer,
which controls said radiotelephone communications transceiver and said
display according to said output signal of said contact-sensitive
transducer; and
a second control circuit, responsive to said contact-sensitive transducer,
which controls power transfer from said power supply to said first control
circuit according to said output signal from said contact-sensitive
transducer.
5. A radiotelephone according to claim 4, wherein said first control
circuit comprises a microcontroller, and wherein said second control
circuit controls power transfer from said power supply to said
microcontroller according to said output signal of said contact-sensitive
transducer.
6. A radiotelephone, comprising:
a housing comprising a front surface and respective first and second edge
surfaces disposed on respective opposite sides of said front surface;
a radiotelephone communications transceiver, supported by said housing;
a display, supported by said housing, that displays an image at said front
surface of said housing;
first and second contact-sensitive transducers, supported by said housing
and having respective contact-sensitive surfaces disposed at respective
ones of said first and second edge surfaces, which produce respective
first and second output signals that characterize contact along respective
ones of said contact-sensitive surfaces of said first and second
contact-sensitive transducers, wherein said first and second
contact-sensitive transducers comprise respective first and second
contact-sensitive strips mounted at respective ones of said first and
second edge surfaces; and
a controller, responsive to said first and second output signals and
operatively associated with said display and said radiotelephone
communications transceiver, which controls at least one of said display
and said radiotelephone communications transceiver according to said first
and second output signals of said first and second contact-sensitive
transducers, wherein said controller has a first mode wherein said
controller is responsive to said first contact-sensitive transducer and
unresponsive to said second contact-sensitive transducer, and a second
mode wherein said controller is responsive to said second
contact-sensitive transducer and unresponsive to said first
contact-sensitive transducer, and further comprising means for placing
said controller in one of said first mode or said second mode.
Description
FIELD OF THE INVENTION
The present invention relates to radiotelephones and methods of operation
thereof, and more particularly, to apparatus and methods for providing
user input to radiotelephones.
BACKGROUND OF THE INVENTION
Radiotelephone terminals typically include a radio transceiver integrated
with a user interface mechanism within a handheld case. The user interface
typically includes a plurality of keys similar to those provided on
conventional wireline telephones, as well as additional function keys for
controlling functions associated with radiotelephone operations. The keys
provide a means for entering commands, telephone numbers or other data for
processing by the radiotelephone. A display may be used to display
information a user has entered at the keys, e.g., telephone numbers, menu
selections, and the like, as well as to display messages or other
information received from a radiotelephone system with which the
radiotelephone is communicating. The display may also be used to display
information stored in memory located in the radiotelephone.
Commonly, the display is configured to display one or more graphical
objects, e.g., a list of commands in a command menu or a list of telephone
numbers that are stored in the radiotelephone memory that the user may
select for communication. The graphical objects may be selectively
displayed, for example, by displaying a selected number of entries in a
list of telephone numbers or command options. The list may be "scrolled"
in response to a user input to allow a large list to be displayed on a
small display.
In some conventional radiotelephones, control of the scrolling of graphical
objects on the display may be controlled by one or more keys, the
operation of which may be similar to the "arrow" keys provided on computer
keyboard. Other keys may be provided to invoke particular selections. In
other conventional radiotelephone designs, a wheel-like input device may
be mounted on the radiotelephone case that may be turned by a user to
effect scrolling of graphical objects on the display. The wheel device may
also be configured to select items on the display in response to user
application of radial pressure to the wheel.
Each of these conventional techniques for control of a radiotelephone
display has its limitations. Keys for scrolling and invoking display
selections may be awkward to use, and may consume valuable space on the
keypad of the radiotelephone. A wheeled input device may provide faster
and more intuitive scrolling control, but such a device may take up an
inordinate amount of space and require moving parts which may be more
prone to failure. Accordingly, there is a need for improved input devices
for radiotelephones.
SUMMARY OF THE INVENTION
In light of the foregoing, it is an object of the present invention to
provide radiotelephones and methods of operation thereof which provide
reliable, intuitive and efficient display control.
This and other objects, features and advantages are provided according to
the present invention by radiotelephones and methods of operation thereof
in which control of a radiotelephone's display and/or radiotelephone
communications transceiver is effected using a contact-sensitive
transducer such as a resistive or capacitive touch strip mounted on the
radiotelephone. The contact-sensitive transducer produces an output signal
that characterizes contact, e.g., contact of an object such as a user's
finger, with a surface of the transducer. The output signal may be
processed by a controller to control display of information on the display
and to initiate actions associated with displayed items. For example, the
contact-sensitive transducer may be used to control display of graphical
objects such as rows or columns on the display, and initiation of
functions associated with the graphical objects. Preferably, the
contact-sensitive transducer comprises an elongate strip and produces an
output signal that characterizes contact with the strip along its elongate
axis. In one embodiment, two of such elongate strips are mounted on
respective sides of the radiotelephone. In another embodiment, an elongate
strip is mounted on a front face of the radiotelephone.
Using a contact-sensitive transducer to control a radiotelephone offers
several advantages. Because a contact-sensitive transducer may be
configured to have a thin profile, the transducer may be mounted at a
surface of the radiotelephone without taking up an inordinate amount of
valuable space. Because characteristic types of contact with the
transducer can be detected, such as swiping motions or taps, the
transducer may be used to perform display movements such as scrolling or
cursor movement, as well as for selection of items displayed on the
display. In addition, because a contact-sensitive transducer may be
fabricated without moving parts, reliability may be improved.
In particular, according to an aspect of the present invention, a
radiotelephone includes a frame. The frame supports a radiotelephone
communications transceiver and a display. A contact-sensitive transducer
such as a resistive transducer, a capacitive transducer or a
semiconductive transducer, is supported by the frame, e.g., mounted at a
surface of a housing, and produces an output signal that characterizes
contact along a contact-sensitive surface of the contact-sensitive
transducer. A controller is responsive to the output signal and
operatively associated with the display and the radiotelephone
communications transceiver, and controls at least one of the display and
the radiotelephone communications transceiver according to the output
signal of the contact-sensitive transducer.
In an embodiment of the present invention, the controller is configured to
selectively display an image, e.g., a graphical object such as a row of
alphanumeric characters, on the display responsive to the output signal of
the contact-sensitive transducer. The controller may include means for
displaying of a plurality of graphical objects on the display, and means,
responsive to the contact sensitive transducer, for identifying one of the
displayed plurality of graphical objects based on the output signal of the
contact-sensitive transducer.
According to another embodiment, the controller comprises means, responsive
to the contact-sensitive transducer, for determining a position of contact
along the axis of the contact-sensitive transducer. Means are also
provided, responsive to the means for determining a position of contact,
for selectively displaying a graphical object based on the determined
position of contact to thereby identify the graphical object, e.g., by
highlighting one of a plurality of displayed graphical objects or by
displaying a cursor that indicates one of a plurality of displayed
graphical objects.
In yet another embodiment of the present invention, the controller is
configured to cause the display or the radiotelephone communications
transceiver to perform a plurality of actions. An action of the plurality
of actions may be associated with an identified graphical object, and the
controller may further comprise means, responsive to the contact-sensitive
transducer, for initiating the action associated with the identified
graphical object. The means for initiating an action may include means,
responsive to the contact-sensitive transducer, for detecting a momentary
contact with the transducer. Means may be provided, responsive to the
means for detecting a momentary contact, for initiating the action
associated with the identified graphical object. The means for initiating
an action may include means for initiating the action in response to
detection of a predetermined number of momentary contacts occurring within
a predetermined time interval.
According to another embodiment of the present invention, the controller
includes means, responsive to the contact-sensitive transducer, for
scrolling displayed rows along an axis of the display based on the output
signal of the contact-sensitive transducer. The means for scrolling may
include means, responsive to the output signal of contact-sensitive
transducer, for detecting moving contact with the contact-sensitive
transducer along the axis of the contact-sensitive transducer, and means,
responsive to the means for detecting moving contact, for scrolling
displayed rows along the axis of the display based on the detected
movement.
In yet another embodiment of the present invention, the controller has a
first mode wherein the controller is responsive to contact with the
contact-sensitive transducer and a second mode wherein the controller is
unresponsive to contact with the contact-sensitive transducer. The
radiotelephone further comprises means for placing the controller in one
of the first mode or the second mode in response to an input from a user.
Another embodiment according to the present invention includes a power
supply electrically connected to the contact-sensitive transducer. The
controller comprises a first control circuit, responsive to the
contact-sensitive transducer, which controls the radiotelephone
communications transceiver and the display according to the output signal
of the contact-sensitive transducer, and a second control circuit,
responsive to the contact-sensitive transducer, which controls power
transfer from the power supply to the first control circuit according to
the output signal from the contact-sensitive transducer. The first control
circuit may include a microcontroller, and the second control circuit may
control power transfer from the power supply to the microcontroller
according to the output signal of the contact-sensitive transducer.
In another embodiment according to the present invention, the
radiotelephone frame includes a housing and the contact-sensitive
transducer comprises an elongate contact-sensitive strip mounted at a
surface of the housing. The housing may have a front face and an adjoining
first side, the display may be mounted at the front face, and the elongate
contact-sensitive strip may be mounted at the first side adjoining the
front face. A second contact-sensitive strip may be mounted at a second
side of the radiotelephone housing, adjoining the front face and opposite
the first side. According to another embodiment, a contact-sensitive
transducer may be mounted at the front face of the housing.
According to method aspects of the present invention, user input is
provided to a radiotelephone using a contact-sensitive transducer that
produces an output signal that characterizes contact of an object on a
contact-sensitive surface of the contact-sensitive transducer. At least
one of a radiotelephone communications transceiver and a display of the
radiotelephone may be controlled according to the output signal of the
contact-sensitive transducer. An image may be selectively displayed on the
radiotelephone display according to the output signal of the
contact-sensitive transducer. Improved user interfaces for radiotelephones
are thereby provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a radiotelephone according to an embodiment of the
present invention.
FIG. 2 is a schematic diagram illustrating a radiotelephone according to an
embodiment of the present invention.
FIG. 3 illustrates a radiotelephone with dual contact-sensitive strips
according to another embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating a circuit for controlling a
display using a contact-sensitive transducer according to another
embodiment of the present invention.
FIG. 5 is a flowchart illustration of operations for determining a position
of contact of an object with a contact-sensitive transducer according to
an aspect of the present invention.
FIG. 6 is a schematic diagram illustrating a circuit for controlling power
supply to a radiotelephone using a contact-sensitive transducer according
to another embodiment of the present invention.
FIGS. 7A-7C illustrate operations for scrolling displayed items and
selecting functions associated with a displayed item according to another
aspect of the present invention.
FIG. 8 is a flowchart illustration of operations for detecting a swiping
contact with a contact-sensitive transducer according to another aspect of
the present invention.
FIGS. 9-10 are flowchart illustrations of operations for detecting contacts
with a contact-sensitive transducer according to aspects of the present
invention.
FIG. 11 illustrates a radiotelephone with a horizontally mounted
contact-sensitive strip according to another embodiment of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention now will be described more fully hereinafter with
reference to the accompanying drawings, in which embodiments of the
invention are shown. Those skilled in the art will appreciate that the
invention may be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather, these
embodiments are provided so that this disclosure will be thorough and
complete, and will fully convey the scope of the invention to those
skilled in the art. In the drawings, like numbers refer to like elements
throughout. It will be understood that when a first object, e.g., a
contact-sensitive transducer strip, is referred to as mounted "at" a
surface of a second object, e.g., a housing or the like, the first object
may be mounted directly on the surface of the second object, on a
structural element or frame underlying the surface of the second object
which allows a surface of the first object accessible through an opening
in the surface of the second object, and the like.
FIG. 1 illustrates a radiotelephone 100 in which the apparatus and methods
according to an embodiment of the present invention may be embodied. The
radiotelephone includes a frame, here shown as including a housing 110.
The housing 110 supports a display 120 and a plurality of keys 130. Those
skilled in the art will appreciate that also included but not illustrated
are a radiotelephone communications transceiver for communicating with a
radiotelephone system, e.g., transmitter, receiver and associated control
circuits for communicating with a cellular system via an antenna 140. The
radiotelephone communications transceiver and the display 120 are
controlled by a contact-sensitive transducer 150 mounted at a side surface
of the radiotelephone housing 110, adjacent the display 120. It will be
appreciated that the contact-sensitive transducer 150 may be attached to
the housing 110 in a variety of different ways. For example, the
transducer 150 may be attached to an outer surface of the housing 110,
attached to a boss or similar structure attached to an outer surface of
the housing 110, attached to a circuit board or similar structure mounted
within the housing 110 and extending through an opening in a surface of
the housing 110, or the like.
Referring now to FIG. 2, the contact-sensitive transducer 150 produces an
output signal 155 that characterizes contact of an object, such as a
user's finger 210, along an axis 150a of the transducer 150. A controller
220 is responsive to the output signal 155 and operatively associated with
the display 120 and a radiotelephone communications transceiver 230. The
controller 220 selectively display an image, such as one or more rows 240
of alphanumeric characters, on the display 120 based on the output signal
155 produced by the contact-sensitive transducer 150. The controller also
controls the radiotelephone communications transceiver 230 according to
the output signal 155. The contact-sensitive transducer 150 may comprise a
variety of different contact-sensitive devices, including resistive,
capacitive or semiconductive strips. For example, the contact-sensitive
transducer 150 may be implemented using a semiconductive pad-type
transducer of the type manufactured by Interlink Corp.
FIG. 3 illustrates an embodiment of the present invention, in which dual
contact sensitive strips 150a, 150b are attached on opposite sides of a
radiotelephone housing 110, adjacent the display 120. By providing strips
on both sides of the radiotelephone housing 110, the radiotelephone 100
may be used in either a right-handed or left-handed fashion. Preferably,
only one of the strips 150a, 150b is active at any given time, i.e., one
of the strips is inactivated to prevent inadvertent generation of signals
to the controller caused by gripping of the radiotelephone. The active
strip may be indicated by, for example, displaying an icon 125 near the
edge of the display 120 closest the active strip 150a.
FIG. 4 illustrates an exemplary embodiment of the controller 220 that
includes a circuit connected to nodes R.sub.1, R.sub.2, R.sub.c, L.sub.1,
L.sub.2, L.sub.c of the transducers 150a, 150b. Voltages between the nodes
R.sub.1 and R.sub.c and nodes L.sub.1 and L.sub.c are sampled under the
control of a microcontroller 410 which controls multiplexers 420a, 420b
and a discharge switch 430, selectively applying the voltages at the nodes
R.sub.1, R.sub.2, R.sub.c, L.sub.1, L.sub.2, L.sub.c to capacitor C. A
comparator 440, in conjunction with a counter 450, determines the time
required to charge the capacitor C to a threshold voltage V.sub.T after a
node of one of the transducers 150a, 150b is connected to the capacitor C.
A trio of charge times is sampled for a given transducer, providing a
measure of a position of contact of an object with the transducer, as will
be described in detail below. The counts produced by the counter 150,
representing contact position samples, are latched into a register 460,
and in turn conveyed to the microcontroller 410 for further processing.
Those skilled in the art will appreciate that a wide variety of apparatus
other than the illustrated embodiment of FIG. 4 may be used with the
present invention. For example, a different type of contact-sensitive
transducer may be employed which utilizes a different kind of controller
circuitry to processes output signals produced by the contact-sensitive
transducer. In general, it will be appreciated that a controller 220 for
processing output signals produced by a contact-sensitive transducer and
for controlling a display 120 and a radiotelephone communications
transceiver 230 according to the output signal, as described with respect
to FIG. 2, may be implemented using special purpose hardware, software or
firmware running on general-purpose or special-purpose computing
apparatus, or combinations thereof.
The flowchart illustration of FIG. 5 illustrates methods and apparatus for
determining a position of contact with a contact-sensitive transducer
according to an aspect of the present invention. It will be understood
that blocks of the flowchart illustration, and combinations of blocks in
the flowchart illustration, can be implemented by computer program
instructions which may be loaded onto a computer or other programmable
data processing apparatus to produce a machine such that the instructions
which execute on the computer or other programmable data processing
apparatus create means for implementing the functions specified in the
flowchart block or blocks. The computer program instructions may also be
loaded onto a computer or other programmable data processing apparatus to
cause a series of operational steps to be performed on the computer or
other programmable apparatus to produce a computer implemented process
such that the instructions which execute on the computer or other
programmable apparatus provide steps for implementing the functions
specified in the flowchart block or blocks. Accordingly, blocks of the
flowchart illustration support combinations of means for performing the
specified functions and combinations of steps for performing the specified
functions. It will also be understood that each block of the flowchart
illustrations, and combinations of blocks in the flowchart illustration,
can be implemented by special purpose hardware which performs the
specified functions or steps, or combinations of special purpose hardware
such as the microcontroller 410 of FIG. 4, microprocessors, digital signal
processing (DSP) chips, application-specific integrated circuits (ASICS)
or the like, which execute computer instructions.
FIG. 5 illustrates exemplary detailed operations (Block 500 et seq.) for
determining a position of contact of an object with the left contact strip
150a of FIG. 3. The discharge switch 430 is closed to discharge the
capacitor C (Block 505). The power supply voltage V.sub.cc is then applied
to the L.sub.1 node (Block 510), and the L.sub.c node is connected to the
capacitor C (Block 515). The discharge switch 430 is then opened to charge
the capacitor C (Block 520), and a first capacitor charge time T.sub.1 is
measured (Block 525). The capacitor C is then discharged by closing the
switch 430 again (Block 530). The power supply voltage V.sub.cc is next
applied to the L.sub.2 node (Block 535), and the L.sub.c node is connected
to the capacitor C (Block 540). The discharge switch 430 is then opened
(Block 545), and a second capacitor charge time T.sub.2 is measured (Block
550). The capacitor C is discharged once again by closing the discharge
switch 430 (Block 555). The power supply voltage V.sub.cc is then applied
to the L.sub.1 node (Block 560), and the L.sub.2 node is connected to the
capacitor C (Block 565). The discharge switch 430 is opened (Block 570),
and a third capacitor charge time T.sub.3 is measured (Block 575). The
first, second and third capacitor charge times T.sub.1, T.sub.2, T.sub.3
are then used to determine a position of contact with the transducer 520b
(Block 580).
In particular, three equations are applicable to the measurements described
with respect to FIG. 5:
T.sub.1 =k(R.sub.L.sbsb.1 +R.sub.L.sbsb.c);
T.sub.2 =k(R.sub.L.sbsb.2 +R.sub.L.sbsb.c);
and
T.sub.3 =k(R.sub.L.sbsb.1 +R.sub.L.sbsb.2),
where
k=-C1n(1-V.sub.i /V.sub.cc).
These equations may be solved for R.sub.L.sbsb.1, R.sub.L.sbsb.2 and
R.sub.L.sbsb.c, and the position of contact P can be determined as:
##EQU1##
Those skilled in the art will appreciate that similar operations may be
performed to determine a position of contact with the right contact strip
150a. It will also be understood that by application of appropriate
control signals to the multiplexers 420a, 420b, either one of the
transducers 150a, 150b may be disconnected from the capacitor C,
effectively preventing input from the disconnected transducer.
FIG. 6A illustrates another embodiment of the present invention,
specifically a circuit which may be used in conjunction with the control
circuit illustrated in FIG. 4 to control power transfer from a power
supply, e.g., a battery supplying a battery voltage V.sub.bat, to the
microcontroller 410 and/or other circuits in a radiotelephone based on
input signals from a contact-sensitive transducer. Additional switches
610a-610d may be provided in the signal paths connecting the nodes
R.sub.c, L.sub.c, R.sub.1, L.sub.1. These switches may be used to connect
the associated nodes to the control input for the switch 620 via diodes
D.sub.1, D.sub.2 (in the case of nodes R.sub.c, L.sub.c) and to the
battery voltage V.sub.bat (in the case of nodes R.sub.1, L.sub.1) in an
"off" state, as shown. In the off state, a power switch 620 disconnects
the battery voltage V.sub.bat from a regulator 630 that provides a
regulated power supply voltage V.sub.cc to the microcontroller 410.
When either of the right or the left strips 150a, 150b is pressed such that
a voltage is produced sufficient to overcome the drop across the
associated diode D.sub.1, D.sub.2 and the input activation voltage of the
power switch 620, the power switch 620 closes and applies the battery
voltage V.sub.bat to the regulator 630. Power is thus provided to the
microcontroller 410. The microcontroller may then latch the power switch
620 into a sustained "on" state by driving a third diode D.sub.3 and by
applying control signals to the switches 610a-610d to connect the nodes
R.sub.c, L.sub.c, R.sub.1, L.sub.1 the appropriate multiplexers as
illustrated in FIG. 4. The microcontroller 410 may return the power switch
620 to the "off" state by inverting the logic on the line driving the
third diode D.sub.3. Because a specific voltage is needed to activate the
power switch 620, accidental activation of the radiotelephone can be
prevented. According to another embodiment illustrated in FIG. 6B, the
circuit of FIG. 6A may be modified such pressure on both of the strips
150a, 150b is required to power up the regulator 630. When the right strip
150b is pressed, the battery voltage V.sub.bat is applied from R.sub.1 and
R.sub.c to L.sub.1. If the left strip 150a is simultaneously pressed, the
voltage is also applied to the control input of the power switch 620
through D.sub.2. Otherwise, the operation of the circuit of FIG. 6B is
similar to that described with respect to the circuit of FIG. 6A.
The conceptual illustrations of FIGS. 7A-7B and the flowchart illustrations
of FIGS. 8-10 illustrate methods and apparatus for determining contact
with a contact-sensitive transducer to identify graphical objects on a
display and for initiating functions associated with the identified
objects. It will be understood that blocks of the flowchart illustrations,
and combinations of blocks in the flowchart illustrations, can be
implemented by computer program instructions which may be loaded onto a
computer or other programmable data processing apparatus to produce a
machine such that the instructions which execute on the computer or other
programmable data processing apparatus create means for implementing the
functions specified in the flowchart block or blocks. The computer program
instructions may also be loaded onto a computer or other programmable data
processing apparatus to cause a series of operational steps to be
performed on the computer or other programmable apparatus to produce a
computer implemented process such that the instructions which execute on
the computer or other programmable apparatus provide steps for
implementing the functions specified in the flowchart block or blocks.
Accordingly, blocks of the flowchart illustrations support combinations of
means for performing the specified functions and combinations of steps for
performing the specified functions. It will also be understood that each
block of the flowchart illustrations, and combinations of blocks in the
flowchart illustration, can be implemented by special purpose hardware
which performs the specified functions or steps, or combinations of
special purpose hardware such as microcontrollers, microprocessors,
digital signal processing (DSP) chips, application-specific integrated
circuits (ASICS) or the like, which execute computer instructions.
FIGS. 7A-7C illustrate operations for controlling display of an image on a
radiotelephone display according to another aspect of the present
invention, in particular, operations for "scrolling" graphical objects,
here shown as rows, on a radiotelephone display 120, and for initiating a
function associated with a graphical object identified on the display 120.
At least one graphical object is displayed on a radiotelephone display
120. As illustrated in FIG. 7B, a user makes a swiping or displacement
motion in contact with a contact-sensitive strip 150 mounted on a side of
the radiotelephone 100, causing the display rows to "scroll" along the
direction of the user's movement. Those skilled in the art will appreciate
that "scrolling" in a generic sense refers to selective display of a row
on the display 120, and may be encompass a number of different graphical
operations. For example, as depicted in FIGS. 7A-7C, a plurality of rows
may be displayed on the display 120, and a selected one of displayed rows
may be highlighted or otherwise identified in response to the user input.
Different rows may be sequentially displayed on the display 120, giving
the appearance of a scrolling movement. In addition, actions such as
scrolling by sequentially highlighting rows or other graphical objects or
moving a cursor to sequentially indicate rows or other graphical objects
responsive to a swiping motion on the transducer 150 may also be employed.
As illustrated in FIG. 7C, a function associated with an item identified
by, for example, highlighting or cursor positioning, is initiated with the
user performs a predetermined number of momentary contacts or taps on the
contact-sensitive transducer 150, as illustrated in FIG. 7C. These
momentary contacts or taps may occur anywhere along the contact-sensitive
transducer 150. Those skilled in the art will appreciate that a number of
variations on the above-described operations may be performed within the
scope of the present invention. For example, instead of providing
multi-graphical object display, the display 120 may be configured to
display only one row at a time, sequentially displaying rows stored in
memory to give the appearance of scrolling.
FIG. 8 illustrates exemplary operations for detecting a swiping contact
with a contact-sensitive transducer (Blocks 800 et seq.). The transducer
output signal is sampled (Block 805). If the sample indicates contact of
an object with the transducer, a starting position P.sub.start of contact
is next determined (Blocks 810-815). The transducer output signal is again
sampled (Block 820), and if contact is still detected, an ending position
P.sub.end is determined (Blocks 825-830). A distance D is then determined
from the starting and ending positions P.sub.start, P.sub.end (Block 835).
If the magnitude of the distance D is less than a minimum distance
D.sub.min, the movement is disregarded and another sample obtained (Blocks
840-820). If the distance D is sufficiently large, however, the controller
determines the direction of the movement by looking at the sign of the
distance D (Block 845). If the distance D is negative, the display is
scrolled in a first direction (Block 850a); if the distance D is positive,
however, the display is scrolled in a second direction (Block 850b). The
ending position is then used as a new starting position (Block 855).
FIG. 9 illustrates exemplary operations (Blocks 900 et seq.) for detecting
a momentary contact or tap on a contact-sensitive transducer according to
another aspect of the present invention. Generally speaking, a momentary
contact or tap is detected by satisfaction of a series of three
conditions: (1) absence of contact with the contact-sensitive transducer;
(2) contact with the contact-sensitive transducer; and (3) termination of
contact with the contact-sensitive transducer within a predetermined time
period. In the exemplary operations shown, a timer T.sub.1 (for example, a
software timer implemented in the microcontroller 410 of FIG. 4) is
initialized (Block 905). The output signal from a contact-sensitive
transducer is sampled (Block 910). If the sampled output signal indicates
that an object is in contact with the transducer, the output signal is
repeatedly sampled until contact is not detected (Blocks 910-915). Once no
contact is detected, the first condition for a tap is satisfied. A second
round of sampling is then initiated, with the output being sampled until
contact is again detected (Blocks 920-925). Once contact is again
detected, the second condition for a tap is satisfied. The timer T.sub.1
is then started (Block 930). As long as contact continues and the time
measured by the timer T.sub.1 is less than a predetermined maximum time
interval T.sub.max, the output of the transducer is repeatedly sampled
(Blocks 935-945). If contact ceases before the timer T.sub.1 exceeds the
maximum time T.sub.max, the third condition for a tap has been satisfied,
and a valid single tap has been detected (Block 550). However, if the
timer T.sub.1 exceeds the maximum time T.sub.max before contact ceases,
the timer T.sub.1 is reinitialized (Block 905) and the detection process
begins anew.
FIG. 10 illustrates operations (Block 1000 et seq.) for detecting a double
tap on the contact-sensitive transducer. A second timer T.sub.2 is
initialized (Block 1010). Once a valid single tap is detected, the second
timer T.sub.2 is started (Blocks 1015-1020). As long as the time measured
by the second time T.sub.2 remains less than a second maximum time
interval T.sub.2max, and no contact with the transducer is detected, the
transducer is repeatedly sampled (Blocks 1025-1035). If the timer has yet
to expire when contact is detected, it is next determined whether the
contact constitutes a valid single tap (Block 1040). If a valid single tap
is detected, a valid double tap has occurred (Block 1045). If not, the
second timer T.sub.2 is reinitialized (Block 1005), starting the detection
process anew.
FIG. 11 illustrates another embodiment according to the present invention,
a radiotelephone 100' which includes a horizontally-arranged
contact-sensitive transducer 150c, here shown mounted on a front fact of
the radiotelephone housing 110, near the display 120. In a manner similar
to that described with respect to the side-mounted transducers of FIG. 3,
the transducer 150c may be used to selectively display column-organized
graphical objects on the display 120 based on contact of an object, e.g.,
a finger or stylus, with the contact-sensitive transducer 150c. For
example, as illustrated in FIG. 11, icons 1110 may be displayed in columns
on the display 120, and may be selectively identified according to contact
with the contact sensitive transducer 150c, using apparatus and operations
similar to those described with respect to FIGS. 4-10. An icon may be
identified by several techniques, such as by highlighting or by displaying
a cursor 1120 adjacent the identified icon. A function associated with the
identified icon may be selected using apparatus and operations manner
similar to those described with respect to FIGS. 7A-7C. Those skilled in
the art will also appreciate that other embodiments may include
side-mounted contact-sensitive strips such as those illustrated in FIG. 3
in combination with a horizontally-mounted contact-sensitive strip as
illustrated in FIG. 11 to provide both row and column-oriented controls
for the display 120.
In the drawings and specification, there have been disclosed typical
embodiments of the invention and, although specific terms are employed,
they are used in a generic and descriptive sense only and not for purposes
of limitation, the scope of the invention being set forth in the following
claims.
Top